Ch 11 Biodiversity Flashcards
Define Biodiversity
Biodiversity is the Variety of Living organisms present in an area.
Importance of Biodiversity?
Essential in maintaining a balanced ecosystem for all organisms since all species are Interconnected so depend on each other.
What is an Environmental Impact Assessment?
Assessment taken in attempt to predict the positive and negative effects of a project on biodiversity in the area.
Levels of Biodiversity
Habitat biodiversity
Species biodiversity - Richness & Evenness
Genetic biodiversity
Explain what is meant by Habitat Biodiversity
Habitat Biodiversity is
the Number of Different Habitats found within an Area.
Each habitat can support a number of different species: the greater the Habitat biodiversity, the greater the Species biodiversity in the area.
Species Richness
Species Richness is
the number of different species living in an area
Species Evenness
Species Evenness is
the relative abundance of individuals of each species living in a community.
Community
A community is
All the Populations of living organisms in a particular Habitat.
Explain what is meant by Genetic Biodiversity
Genetic Biodiversity is
the Variety of Genes that Make up a Species.
Greater Genetic Biodiversity provides species with a survival advantage as it allows for better Adaptation to a changing environment, and is likely to result in Individuals Resistant to Disease
Alleles lead to genetic biodiversity within a species
What is Sampling?
What are they Types of Sampling?
Sampling is
taking measurements of a limited number of individual organisms present in an area.
Random, Systematic and Stratified.
Random Sampling
= Selecting individuals by Chance - each individual in population has equal chance of selection.
- mark out grid on area to be sampled using tape measures laid at right angles
- use random number generator to determine x and y coordinate on grid.
- Take a sample from each coordinate pairs generated.
- Repeat
Non-Random Sampling
non-random samlpling = selecting samples based on subjective judgment rather than random selection.
OPPORTUNISTIC - weakest as not representative
STRATIFIED - divide populations into strata based on a particular characteristic and take random samples from each
SYSTEMATIC - areas of overall habitat are identified and sampled separately. Used to study change over distance. Belt or Line transect.
Why is a Sample Never entirely Representative of all organisms present in a Habitat?
Sampling Bias - bias selection process; reduce by using random sampling.
Chance - organisms selcted may, by chance, not be representative of the whole polulation. Chance cannot be completely removed, but its effect can be minimised by using a larger sample size.
Animal Sampling Techniques
Pooter - catch small insects. Suck on mouthpiece to draw insects into holding chamber.
Sweep Nets - catch insects in long grass.
Pitfall Traps - catch small crawling invertebrates. Hole dug in ground, insects fall in and cannot crawl out. Cover with roof structure so that hole doesn’t fill with rainwater.
Kick Sampling - study organisms in a river. Kick river bank to disturb substrate and net is held downstream to capture organisms released.
Tree Beating
Plant Sampling Techniques
Frame Quadrat - square frame divided into grid of equal sections. The type and abundance of species within each section is recorded.
Point Quadrat - at set intervals along the horizontal bar long pins are pushed through to reach the ground and each species the pin touches is recorded.
Use identification key to accurately identify species.
